If your De’Longhi coffee machine is not frothing milk, the issue is usually caused by a blocked milk system, poor cleaning, or incorrect setup rather than a major fault. In most cases, the machine is still producing steam, but the milk is not being textured correctly, resulting in little to no foam or large, bubbly milk. This is commonly due to dried milk residue blocking the frother, air intake, or milk carafe components, which prevents the correct mix of air and steam. Using the wrong milk type or temperature can also impact performance. Regular cleaning of the milk system and ensuring all parts are clear and correctly fitted will resolve most problems, while ongoing issues may indicate worn components or reduced steam efficiency.